Interpretive Summary: Metformin is used to treat non-insulin dependent diabetes in obese patients. In addition metformin also reduces feed intake and body weight. These studies were performed to determine if metformin possesses similar properties in chickens. Metformin was administered to 14-day old broiler chickens at either in the drinking water for 10 days while monitoring body weight and feed intake. No changes in water intake were observed, while feed intake and daily gains were only significantly reduced. After oral administration of a single dose of metformin, feed intake was significantly reduced by 4 hours and remained suppressed for greater than 24 hours relative to controls. Plasma hormones and metabolites were monitored. Significant and acute decreases in blood glucose, insulin, and triglycerides were observed at 3 hours post treatment as compared to controls. Opposing acute increases in glucagon, IGF-II, and NEFA levels were also observed at 3 hours, followed by an increase in uric acid 6 hours post treatment. These observations suggest that metformin induces metabolic changes in birds, similar to that observed in mammals. Metformin may be useful in glucose metabolism studies by inducing hypoglycemia, a condition rarely observed in birds.

Technical Abstract:
The bi-guanide metformin is used to treat non-insulin dependent diabetes in obese patients. In addition to having anti hyperglycemic effects, metformin is also anorectic and reduces body weight. These studies were performed to determine if metformin possesses similar properties in chickens. Metformin HCL was administered to 14-day old broiler chickens at either 300 or 600mg/kg/day in the drinking water for 10 days while monitoring body weight and feed intake. No changes in water intake were observed, while feed intake and daily gains were only significantly reduced by the 600 mg/kg dose. After oral administration of a single dose of 300 mg/kg metformin HCL, feed intake was significantly reduced by 4 hours and remained suppressed for greater than 24 hours relative to controls. Plasma hormones and metabolites (glucose, lactate, insulin, glucagon, IGF-I, IGF-II, uric acid, NEFA, triglycerides, and cholesterol) were monitored at 1, 2, 3, 6, and 24 hours post treatment. Significant and acute decreases in blood glucose, insulin, and triglycerides were observed at 3 hours post treatment as compared to controls. Opposing acute increases in glucagon, IGF-II, and NEFA levels were also observed at 3 hours, followed by an increase in uric acid 6 hours post treatment. These observations suggest that metformin induces metabolic changes in birds, similar to that observed in mammals. Metformin may be useful in glucose metabolism studies by inducing hypoglycemia, a condition rarely observed in birds.